they are 316 1/2"x20 stainless bolts from McMaster. I don't believe there is a high strength stainless bolt. There are other "sort of stainless" alloys that are stronger but that's getting kind of esoteric. If I am incorrect please let me know what I should be using.
The only problem on getting advice on the height is I am one of the very few people who are running a single.
I saw this boat online and it looks like they have the engine in the same place I do, 1998 ZODIAC HURRICANE 733 | Boats for Sale